crackpot

Mostly likely a back-etymology of pot, to form crack +‎ pot. Originally, from crack +‎ pate.

crackpot (plural crackpots)

(informal) An eccentric, crazy or foolish person.
Synonyms: crank, crazy, kook, live one, nut ball, nutbag, nutbar, nutcase, nutter; see also Thesaurus:strange person, Thesaurus:mad person

Time will tell whether he is a crackpot or a genius for promoting that sort of idea.
- 1964, Jean Merrill, The Pushcart War:
  The Police Commissioner sat studying Frank the Flower for several minutes. Then he called the policeman who had arrested Frank. “You will have to lock this man up,” he said. “But treat him gently. He is a harmless crackpot.”
- 1991, “Gaston (Reprise)”, in Howard Ashman (lyrics), Beauty and the Beast:
  No one plots like Gaston / Takes cheap shots like Gaston / Plans to persecute harmless crackpots like Gaston
- 2025 June 12, Michael S. Rosenwald, “Amanda Feilding, Eccentric Countess Who Backed Psychedelic Meds, Dies at 82”, in The New York Times‎, →ISSN, archived from the original on 12 June 2025:
  In the early 1990s, Ms. Feilding realized that the only way to overcome the taboo of these drugs — and her reputation as a crackpot — was to start a scientific foundation to fund research projects that governments and universities would never consider.
(informal) Someone addicted to crack cocaine (i.e. a drug addict).
Synonyms: crackhead, crack whore; see also Thesaurus:addict

crazy person

crackpot (comparative more crackpot, superlative most crackpot)

eccentric or impractical

English